This invention relates to control apparatus for selective multi-color dyeing of individual yarns and producing therefrom a predetermined complex design in a tufted carpet. The invention particularly relates to carpets made by machines commonly called tufting machines in which yarns fed to individual needles of a continuously reciprocating bank of needles are pushed through a backing sheet to form tufts, stitches or loops that may be cut or remain as uncut pile in the finished carpet.
Heretofore, many variations of tufting machines have been developed which are capable of producing cut or uncut pile of uniform or different heights. A large variety of designs have been produced using one or more or all of said varieties of pile, as well as including color variations.
When using differently colored yarns which have been pre-dyed in bulk, practical considerations have limited production of many desirable designs. When producing floral, modernistic, oriental or other complex designs, different colors have been sprayed on the pile of completed carpets, or have been printed in various ways thereon, to produce the desired design. However, problems have arisen in applying the dyes to finished pile, due to inability to penetrate the pile and to apply the dyes evenly and completely and only in the areas (sometimes very small) where the dye should be and remain.
It has been proposed to apply different colored dyes to the individual yarns at spaced predetermined positions along their lengths, determined with reference to a pattern or design that is ultimately to appear in the finished tufted carpet. Such proposals have generally been impractical and commercially unsuccessful, but one proposal that has succeeded in accomplishing this desired result is disclosed in U.S. Pat. No. 4,015,550, in the names of Bartenfeld, Bryant and Newman for "Apparatus and Method for Selective Multi-Color Dyeing of Individual Yarns and Producing Therefrom a Predetermined Complex Design in a Tufted Carpet". U.S. Pat. No. 4,015,550 is commonly owned by the assignee of the present patent application.
In the above-referenced patent, a multiplicity of yarns are dyed individually at different places along their length with different colors, and are delivered to a tufting machine and fabricated into a carpet bearing a predetermined complex design. This is accomplished without interruption and without variation of the relationship of the yarns, one to another. The yarns are led from a supply in the form of a sheet of yarn and are passed individually over a series of spaced dye pick-up rolls rotating in spaced dye baths of different colors. In the course of the passage, the yarns are lowered into contact with the pick-up rolls by yarn control assemblies for predetermined limited times to cause predetermined variable lengths of the individual yarns to be individually dyed. The colors and lengths of the dyeing are determined by the desired pattern that is to appear as the dyed segments of yarn become loops, tufts or stitches in the carpet fabric.
After dyeing, the sheets of yarns may enter a steam chamber wherein the dye is fixed in the yarn and a drying chamber from which the yarns are individually fed through identical length guide tubes to the conventional tufting machine. Throughout these operations, the positions of the individual dyed yarns relative to one another are maintained so that as they enter the tufting machine they will have the same relationship as when the dyes are applied. Thus, in the carpet fabric, the colored tufts appear in a relationship or pattern which was predetermined before the dyes were applied.
In the above-referenced patent, the pattern controlling the dyeing is laid out on a plurality of drums, one for each dye color. The pattern for each color is prepared and laid out on its respective drum, and controls (through conductive and non-conductive areas, and switch fingers) the lowering of each individual yarn into contact for the predetermined time with the dye pick-up roll for that particular color. A separate pattern drum for each dye color is required because of space problems and overlapping control lines due to hundreds of yarn control assemblies required to lower the individual yarns into contact with particular dye pick-up rolls. Further, due to the longitudinal spacing along the length of the machine of the yarn control assemblies and dye rolls, the zero or starting point of the patterns as laid out on the pattern drums is different on each drum. In other words, the controlling action of the drums must be coordinated; and the start of the patterns on the drums for the dye pick-up rolls displaced down the machine from the first dye pick-up roll must follow the start of the first drum by the amount of time taken for the yarn to travel from the first dye pick-up roll to the succeeding dye pick-up rolls.
The present invention is directed to a highly versatile electronic control system which also eliminates the need for the several pattern drums.